Separators for pneumatically conveyed aggregate goods



E. WIDMER Sept. 2, 1958 SEPARATORS FOR PNEUMATICALLY CONVEYED AGGREGATE GOODS Filed Aug. 10, 1955 2 Sheets-Sheet 1 INVENTOR E/V/L h//DME/ BY@ g ATTORN EY Sept. 2, 1958 E. WIDMER 2,850,162

sEPARAToRs FORKPNEUMATIGALLY coNvEYED AGGREGATE Goons Filed Aug. 1o. 1955 2 Sheets-Sheet 2 '7 l j 53 I 5% dner INVENTOR 'mz W United Sw@ Patent Ofi-@ Patented Sept. 2, 1958 2,850,162 sEPARAToRs FoR PNEUMATICALLY coNvEYED AGGREGATE GooDs EmilY Widmer, Uzwil, Switzerland, assignor to Gebruder Buhler, Uzwil, Switzerland Application August 10, 1955, Serial No. 527,600

Claims priority, application Switzerland August 11, 1954 8 Claims. (Cl. 209-134) This invention relates to separators, and more particularly to separators `for pneumatically conveyed aggregate goods wherein the goodsare cleaned and sorted by .the conveying medium.

Recent types of separators for cleaning and sorting pneumatically conveyed goods, such as grains or powdery substances, are based on the recognition that it is particularly advantageous toclean and sort the conveyed goods in a single step by means of air, to wit: by employing the principle of air sifting.- The more economical systems use the conveying medium for cleaning and sorting of goods. In known devices of this character, the aggregate goods are separated from the air by means of an impact separator and thereupon. permitted to descend as a thin veil from a chamber, and the conveying mediuml is guided ltherethrough to carry away the lighter components, such as dust, chaf, etc., thereby cleaning the goods and sorting the diverse components according l goods, these foreign particles again `adhere to the larger grains and are not carriedaway by' the conveying me- The present inventionrepresents an improvement over such prioi separators in that it provides a labyrinth system in'which the impurities `retained from the conveying step are separated from the conveying medium, and the clean conveying medium is then reintroduced through the separated aggregate goods to remove the remaining impurities therefrom.

The invention also provides a system in which the conveyed, separated and partially cleaned goods descend in a chamber with a mobile bottom wall to form a narrow aperture, and the goods, descending therethrough in a thin veil, are again subjected to the meanwhile purified conveying medium to remove the remaining impurities therefrom. t

The invention further provides a system wherein the velocity of the conveying medium may be controlled by varying the cross-sectional area of the duct leading to the exhaust opening of the separator.

Still further, the invention provides a system wherein a bailie is installed below the impact separator to facilitate the sorting of separatedgoods and the removal of lighter impurities by the conveying medium.

An additional feature of the novel separator is in the provision of a dust collecting device at the exit end of the aspirating opening for removal of impurities and other lighter matter from the conveying medium.

The novel separator consists essentially of an airtight housing with an inlet for the conveying medium carrying the aggregate goods about to be cleaned and sorted in the separator, an impact separator chamber with a dellecting device and preferably a baffle member in stalled therein, the bottom of the chamber being pivotally attached to provide an elongated opening for passage of partially cleaned and sorted goods in a thin veil, a duct leading from the chamber with an arcuate portion and an adjustable passage therein. The conveying medium, usually and hereinafter referred to as air, carrying lighter impurities from the impact separator chamber, passes through the arcuate portion of the duct and the impurities following the outer peripheral wall thereof by centrifugal force enter the passage provided therein and are led through a conduit to the aspirating opening of the separator. The cleaned air is then introduced through the thin veil of goods descending from the chamber to removeany remaining impurities and undesirable lighter matter therefrom. Before entering the aspiration opening, the air is led through a duct portion whose cross-sectional area may be controlled to regulate the velocity of air.

Other features and advantages of the novel separato will be pointed out in the course of the following detailed description of one at this time preferred embodiment which is illustrated in the accompanying drawing, and the invention will be linally pointed out in the appended claims.

In the drawing, v Fig. l is a vertical section through the separator; and Fig. 2 is a somewhat Vschematic illustration of the device shown in Fig. l combined with a dust cyclone and a blower. In Fig. l, the illustrated separator 33, which is shown in vertical section, includes an inlet 1 leading into the impact separator' chamber 3 with a deilector plate 2 in the path of goods 21, and a pivotable'plate 5 as the bottom member of said chamber. Wall 7a of duct 7 is inwardly curved at its lower end 4 to form a simple bafe for goods 21 rebounding'on plate 2. As illustrated, the heavier and larger particles carried by the air through inlet 1 rebound on plate 2 and are separated from the air in chamber 2 by descending onto the mobile bottom 5 which yields under a predetermined weight to form an elongated slot 6 between its free end and the lower extremity of wall'7b of duct 7. The air follows the route indicated by continuous arrow 22 and passies through the whirled goods 21 below member 4 before entering vertical duct 7, whose portion 11 is arcuate,

carrying with it line impurities 23, such as dust and chaff, which impurities by centrifugal force concentrate along the outer peripheral wall of the arcuate duct portion 11 to be absorbed into exhaust channel 13 through an adjustable passage 12, and to be thereupon aspirated through opening 10 by a blower 31 (see Fig. 2) or any other suitable device. As indicated, passage 12 is adjustable by moving ap 16 by means of a screw and hand wheel 17. The mass of air, now free from impurities 23, enters the left-hand vertical portion of channel 7 formed by walls 7c and 7d and passes below member S through veil 8 of goods 21 descending through aperture 6 to be deposited in the bottom of the separator 33. Any remaining lighter matter is removed from the veil 8 of goods 21 and is carried away by the air through duct 9 and exhaust opening 10. The cross-sectional area of duct 9 may be varied by screw and hand wheel 19 moving members 14 and 15, as indicated in dotted lines, to control the velocity of the air. An air lock 18 seals the separator and serves for removal of cleaned and sorted goods 21. A dust collector, such as a cyclone 34 (see Fig. 2), maybe placed behind the aspiration opening 10.

It will be understood that the passage 12 may be provided at any point of the arcuate portion 11 of duct 7. Also, a diiferent eddying device may be substituted deposited on plate -5, or a 'permanent slot 6 may be provided between members 5 and' 7 b. the baflle4 maybeomitted entirely.

In the latter case,

The sucking passage 12 should belarge enough to :allow removal of all the impurities 23 therethrough and into channel 13. On the other hand, `this passage 12 should berelatively small as compared with the` cross- -sectional area of duct 7 in order to introduce a large lquantity of purified air through the veil 8 of goods 21.

In Fig. 2, conveying line 32, communicating with inlet r1 of the separator 33, aspirates the goods 21 directly from heap 37 through its intake 35. Adjacent to exhaust opening 10 is a dust cyclone 34 which is also connected to a blower 31 having an outlet 36. Blower 31 generates an underpressure in the system formed by the `conveying line 32, separator 33 andthe cyclone 34 causing the flow of air into intake 35 of line 32 and its escape through the outlet 36 of blower 31. Theflowing air takes up -the goods 21 from heap 37and leads the 'material into separator 33 wherefrom the normal parvticles are discharged Vthrough the air lock 18. Smaller nimpurities flow through outlet 10 of separator 33 into the dust cyclone 34 to be separated from the conveying air and discharged through the air lock 38. Thus, the conveying air escaping through outlet'36 of blower 31 `is clean.

As various changes and modifications in the details of construction, arrangementof parts and substitution of similar or equivalent elements may occur to persons skilled in the art, I do not desire to be limited to the exact details of the device shown and described, but only by the scope of the appended claims.

What is claimed is:

1. In a device for cleaning and sorting pneumatically conveyed aggregate goods havinga housing, an inlet Aand-an aspiration opening: an impact separator chamber,

a deecting member in said chamber in the path of pneumatically conveyed goods entering through said in- `let opening, said chamber having an elongated aperture substantially in the bottom portion thereof for descent `of aggregate goods separated from the conveying medium, a labyrinth duct for the conveying medium in said housing communicating with said chamber between said de- -flecting member andsaid aperture, said -duct thereupon extending around said chamber and below said aperture and terminating at said aspiration opening, and means for separating impurities from the conveying medium in said duct in advance ofthe passing of said duct below `said aperture in saidchamber.

2.A device according to claim 1, further including means for varying said aperture in said chamber.

3. A device according to claim 1, wherein said chamber has a bottom wall, vmeans pivotally connecting said bottom wall with said chamber and resilient means for urging said bottom wall against said chamber whereby to control said aperture in said chamber.

4. A device according-to claim 1, wherein said duct includes an arcuate portion in advance of its passing below said aperture in said chamber, said arcuate portion having an aspirating passage in the outer peripheral wall thereof, and a conduit Vis provided for connectingsaid aspiratingpassage with' said aspiration opening.

5. A device-according to claim 4, further including means for varying said aspirating passage insaid arcuate portion ofsaid duct.

6. A deviceaccording to claim 1, further including a -bafe'member in said chamber below said deflecting'mem- -ber and above the communication of said duct withl said chamber, said baffle member being in the path of con- -veyed goods descending' from said deflecting member to- :ward said aperturefor-eddying same, whereby the conveying medium entering said duct removes lighter matter itherefrom.

7. Adevice according to claim 1,4 further including au air lock Yin thebottom of saidhousing -for removal of Vconveyed and cleaned-goodsrfrom saidhousing .8. `A device according' to claiml 1, further including a dust separating device for the cleaning medium in the proximity of Vsaid aspiration opening.

.References Cited inithetile of this patent UNITED STATES'PATENTS 

